Aircraft gas turbine engine combustors receive air at a high pressure from the compressor of the engine. Because of this, fuel must be pumped such that the fuel pressure is high enough to spray through the nozzles and satisfy the needs of the combustor. Larger aircraft engines may include as many as thirty or more fuel nozzles to provide fuel to the combustor. It is desirable to adjust the fuel flow to each fuel nozzle individually to achieve optimum engine performance.
To control the fuel flow, a metering unit may be implemented to meter fuel from a main pump to each fuel nozzle. Each metering unit may include an intelligent device, such as an electronic microcontroller. Traditionally, power and communication must be provided to each metering unit from a primary power source. Thus, a system comprised of several metering units will incur cost, weight, space, and reliability penalties due to the abundance of wiring and interconnections. Power supplies used to power these modules also create greater complexity as more hardware is typically needed to handle failure modes.